Excavation cutting tool assemblies for such applications as continuous mining or road milling typically comprise a cutting tool, sometimes referred to as a cutting bit, rotatably mounted within a cutting tool holder, sometimes referred to as a cutting tool sleeve, bit holder, or bit sleeve. In such assemblies, the cutting tool holder is mounted within a support block. The support block in turn is mounted onto a drum or other body, typically by welding, which in turn is driven by a suitable power means. When a number of such support blocks carrying cutting tool holders and cutting tools are mounted onto a drum, and the drum is driven, the cutting tools will engage and break up the material which is sought to be mined or removed. The general operation of such a mining machine is well known in the art.
As mentioned, the cutting tool holder may be mounted within the support block, typically via some mechanical connection. For example, U.S. Pat. No. 5,769,505 to Siddle and Massa discloses a cutting tool holder which may be connected within the support block bore via a pin threadably mounted to the support block. The portion of the pin extending into the support block bore has a generally conical shape and engages the cutting tool holder such that when the pin is rotated so as to move the pin into the block bore the conical shape will engage the cutting tool holder so as to draw the cutting tool holder into the support block bore.